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  • Author or Editor: H. H. Someda x
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Summary  

The sorption of uranium-Arsenazo III complex was studied using Dowex-1x8 and carbonized apricot stone. The results show a similarity between the two sorbents since the percentage uptake of a uranium complex in the ratio 1 : 1 reaches 100% and 92% on the Dowex-1x8 and the carbonized apricot stone, respectively. Also the uptake of the complex on either sorbents increases with increasing the hydrogen ion concentration to reach  a maximum value at pH 2.5. The two sorbents are used to study the sorption of uranium(VI) from seawater in the presence of 0.002% of Arsenazo III and 10-3M EDTA, where it is found that uranium is completely sorbed by the two sorbents.

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Abstract  

Uranium is considered to be one of the most important elements used in nuclear technology. Different authors have worked deeply with developing the methods and materials used for uranium separation, concentration, and refining. In this work, uptake and release behavior of uranyl ions by wood powder from nitrate medium was studied. The factors affecting both processes were discussed.

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Abstract  

The extraction of Co(III) has been studied from acetate medium by acetylacetone in CHCl3. The effect of adding different synergetic bases (S) like diisobutyl ketone, dibutyl ether, diisobutyl carbinol and tributyl phosphate was studied. The extracted species is Co(OH)2 (AcAc)·2HAcAc by acetylacetone only while the species formed for the mixed extractants are Co(OH)2 (AcAc)·(HAcAc) (S)n where n=1 or 2. The corresponding thermodynamic parameters were determined and discussed.

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Abstract  

Dibutyl N,N,-dibutylcarbamoylmethylphosphonate (DBDBCMP) has been used in the extraction study of Eu(III) from low acidic solutions. The different parameters affecting the distribution ratio have been studied. The reaction is considered as a chelate interaction and the extracted species are Eu(OH)2 DBDBCMP·2HDBDBCMP and Eu(NO3)2 DBDBCMP. HDBDBCMP from perchlorate and nitrate, respectively. The equilibrium constants corresponding to the different species formed are calculated and discussed. The effect of changing diluent on extraction capacity of the phosphonate is also studied and discussed.

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Abstract  

The extraction of Co/III/ by benzoylacetone solutions has been carried out from acetateacetic acid solutions. The effect of different parameters affecting the distribution coefficient of Co/III/ have been determined. Lg D for Co was found to be a third order dependent on extractant concentration and a negative first order with respect to [H+]. From the thermodynamic parameters and the data of distribution ratios, the extraction mechanism has been suggested. Addition of some electron donor compounds shows no possibility for the increase of coordination number.

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Abstract  

The extraction of UO 2 2+ from nitrate solution has been carried out using DHDECMP. Different parameters affecting the distribution coefficient of UO 2 2+ have been determined. The extraction of UO 2 2+ was found to have second order dependency on both extractant and H+ concentrations. Addition of some bases as TBP and TOPO to the phosphonate extractant increased the distribution of UO 2 2+ to a great extent. LogD for UO 2 2+ with respect to both synergistic bases was found to be a first order dependent. The thermodynamic parameters have been calculated and the extraction mechanisms have been suggested.

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Abstract  

Apricot stone shells were carbonized under certain chemical and thermal conditions to produce sorbents having a quantitative affinity to retain some radioactive nuclei. The sorbent shows a thermal stability upto 500 °C. The diffraction patterns clarify that the sorbent is mainly amorphous in structure. Carbon in these shells was elementally analyzed and the data reveal a predominant content of acidic surface centers with hydrophilic properties. The isoelectric point (pHPZC) was determined and found to be 4.2 implying the acidic nature of the sorbent surface. The sorption of Cs+, Co2+ and Eu3+ on the prepared sorbent was studied from aqueous solution under different variables and the sorption capacity had values from 0.23-1.15 meq/g.

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Summary  

8-Hydroxyquinoline in benzene, xylene, chloroform and toluene diluents was used to modify silica gel as a solid phase extractant (SPE) for the sorption of Eu(III) in batch extraction techniques. Influences of solid/liquid ratio, pH, metal ion concentration, particle size and temperature were studied. The optimum initial pH is 4.2, while the maximum sorption capacities for the prepared impregnated resins in benzene, xylene, chloroform and toluene diluents are 18.52, 14.98, 14.79 and 5.94 mg . g-1, respectively. The sorption process is found to be affected by both metal ion concentration and particle size of the impregnated resin. Thermodynamic parameters for the sorption of Eu(III) were determined and the reaction is found to be exothermic and spontaneous with enthalpy-14.23 and-23.71 kJ . mol-1 for benzene and xylene as diluents. Release of the element from the loaded solid particles into 0.01M HNO3 is@85% and@53% from 8-HQ/benzene/silica gel and 8-HQ/xylene/silica gel.

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